another bathroom extractor question

[Apache]

i was specifically speaking of the fan where did i mention the metal back box? :innocent if you want to educate you need to explain so they don't pick up on your bad habits.you've just virtually told them they can use the earth as a line conductor but its bad practice:coat

obviously you would earth the metal back box from there you would take only live and neutral to the fan. the only cables that require an earth as you put it are metallic covered cables such as swa.

Lostit - Batty makes more sense here. There was no confusion from me - a rank amateur. Take the cpc with the cable, no suggestion of using it as a live conductor

 

[Lee321]

no no lads.

batty was suggsting i was suggesting using it.

clearly not further more he actually describes how it could work giving people ideas but then gives me a bollicking!

as i said if the fan is not a run on and class 2 you could simply take 2 single pvc/pvc cables to the fan

 

[JUD]

I'd just wire it as if it was a class I fan with timed over run. Any wires you don't need at the fan can always be terminated in a connector block. This way (as has already been mentioned) if the customer wanted to change it in the future then all the wires are there ready to go.

3&E (Perm. Live, Sw. Live, Neutral & CPC) to 3 pole isolator. From isolator in 3&E to fan. If you don't need Perm. Live and/or CPC for fan terminate in connector block. Sw. Live & Neutral into fan.

Bob's your auntie:coffee

 

[Risteard]

And anyway surely it's good practice to include a CPC

Not good practice but in fact a requirement of the Regulations.

 

[batty]

We are talking about a bathroom fan here so it will need an over run to get rid of condensation unless you are going to put one in with a humidstat. Now it will probably need three cores to make it work so generally you will use 3 core and earth it will probably be double insulated so does not actually require an earth. I was pointing out that all cables need earthing but Mr Lostit keeps saying its double insulated so technically only needs 3 cores so the options are to wire it in 3 core flex but this way you would have to use green/yellow as a live which does not comply with regs or do as I would use 3core and earth and terminate cpc in connector block.

 

[Lee321]

We are talking about a bathroom fan here so it will need an over run to get rid of condensation unless you are going to put one in with a humidstat. Now it will probably need three cores to make it work so generally you will use 3 core and earth it will probably be double insulated so does not actually require an earth. I was pointing out that all cables need earthing but Mr Lostit keeps saying its double insulated so technically only needs 3 cores so the options are to wire it in 3 core flex but this way you would have to use green/yellow as a live which does not comply with regs or do as I would use 3core and earth and terminate cpc in connector block.

batty you could use single core pvc pvc

 

[Dambo]

Just to get this right guys - If taking the feed from the light to the 3 pole isolator switch, do you use 2 core and earth (switch live and neutral) or 3 core and earth (live, switch live and neutral)?

 

[Apache]

Just to get this right guys - If taking the feed from the light to the 3 pole isolator switch, do you use 2 core and earth (switch live and neutral) or 3 core and earth (live, switch live and neutral)?

You need a switched live, a permanent live and a neutral from somewhere.

Depends where you tap off as to what cable you would use, if a convenient JB/ceiling rose with all accessible then 3 core and earth would be fine.

 

[batty]

Just to get this right guys - If taking the feed from the light to the 3 pole isolator switch, do you use 2 core and earth (switch live and neutral) or 3 core and earth (live, switch live and neutral)?

If its a timer fan it will need three core and earth other fans with no over run two core and earth.

 

[Dambo]

Thanks guys. 3 core and earth from light to isolator then isolator to fan it is then!

 

[sparkytim]

Thats it

 

[Dambo]

One final final question!

Is 1.5mm 3 core and earth suitable? It's just that the isolator fan paperwork seems to suggest that 1.0mm should be used.

 

[sparkytim]

If 1mm is ok then 1.5 can only be ok too.

 

[batty]

One final final question! Is 1.5mm 3 core and earth suitable? It's just that the isolator fan paperwork seems to suggest that 1.0mm should be used.

I always use 1.5mm on lighting circuits but have started putting 1.0mm to fans as the terminals are not too big and sometimes 1.5mm can be a pig to get in the terminals.